import java.util.Scanner;

/**
 * @author gao
 * @date 2025/8/27 15:20
 */

public class Solution {
    public int bulbSwitch(int n) {
        return (int) Math.sqrt(n);
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNext()) {
            int n = in.nextInt();
            Solution solution = new Solution();
            System.out.println(solution.bulbSwitch(n));
        }
    }
}